/*
 * @(#)ShellHelp.java	1.0 Apr 18, 2008
 *
 *	The MIT License
 *
 *	Copyright (c) 2008 Malachi de AElfweald <malachid@gmail.com>
 *
 *	Permission is hereby granted, free of charge, to any person obtaining a copy
 *	of this software and associated documentation files (the "Software"), to deal
 *	in the Software without restriction, including without limitation the rights
 *	to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 *	copies of the Software, and to permit persons to whom the Software is
 *	furnished to do so, subject to the following conditions:
 *
 *	The above copyright notice and this permission notice shall be included in
 *	all copies or substantial portions of the Software.
 *
 *	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 *	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 *	FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 *	AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 *	LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 *	OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 *	THE SOFTWARE.
 */
package org.eoti.io.console.shell.cmd;

import org.eoti.io.console.shell.ShellException;
import org.eoti.io.console.shell.ShellExtension;

import java.util.*;

public class ShellHelp
		extends ShellExtension
{
	public ShellHelp(){
		super();
	}

	protected void computeFormat()
	{
		if(shell == null)
		{
			super.computeFormat();
			return;
		}

		int col1 = 1;
		for(String name : shell.getExtensions().keySet())
			col1 = Math.max(col1, name.length());

		int col2 = getConsoleWidth() - col1 - 5;
		setFormat("  " + defaultFormat(col1) + ":  " + defaultFormat(col2) + "\n");
	}

	public void execute(List<String> arguments)
			throws ShellException
	{
		if(arguments.isEmpty())
		{
			computeFormat();
			shell.format("Available Commands:\n");
			for(String name : shell.getExtensions().keySet())
			{
				ShellExtension ext = shell.getExtension(name);
				format(name, ext.getUsage());
			}
			shell.format("%d extensions found.\n", shell.getExtensions().size());
			shell.println();
			return;
		}

		if(arguments.size() > 1)
			error("Incorrect format. Try 'help' or 'help command'.");

		String cmd = arguments.get(0);
		ShellExtension ext = shell.getExtension(cmd);
		if(ext == null)
			error("Unknown command: %s", cmd);

		shell.format("HELP %s:\n", cmd);
		ext.manual();
		shell.println();
	}

	public String getName()
	{
		return "help";
	}

	public String getUsage()
	{
		return "'help' for list of commands\n'help command' for detailed information.";
	}
}
